Today, I was fired from a job I didn't know I had. That is to say, the company hired me but didn't tell me, so when I didn't show up for work two days in a row, they called and claimed job abandonment. FML

Where does it say that OP didn't call and ask? He could have asked and they told him the generic, "we're still interviewing and we'll give you a call soon." OP probably never got that call. Moreover, some higher end jobs don't even allow you to call to check on your status, not even a call to HR. So let's not jump to conclusions. The organization is at fault for not disclosing that information. Shit, they might have even 'fired' the wrong person.

If that truly is the case, it sounds like they’ve got their heads up their disorganized asses, and you’re lucky to have dodged a bullet. Sounds like the kind of company that could routinely forget to issue payroll, or send in tax deductions. My guess is that had you worked there long enough, you’d have gotten completely screwed over due to managerial incompetence.